Alysson labrisectus Zou and Li, 2025

Alysson labrisectus Zou and Li , sp. nov.

( Figure 2 View FIGURE 2 )

Type materials. Holotype, ♂, China: Ningxia Autonomous Region, Erlonghe Forest Farm, Botanical Garden , 2008. VI.3, collected by Ma Li.

Diagnosis. This new species resembles A. ratzeburgi Dahlbom, 1843 in having median furrow of frons conspicuous and reaching anterior ocellus, and all legs yellow or brown except hind coxa largely black. It can be distinguished from the latter by the following characters: free margin of clypeus depressed medially (free margin of clypeus straight in A. ratzeburgi ); propodeal enclosure as long as propodeal dorsum (propodeal enclosure about as long as 4/5 of propodeum in A. ratzeburgi ); clypeus largely black, long spot on lower frons laterally light gray white, fore coxa brown, pair of round spots on gastral tergum II anterolaterally light yellowish brown and evidently smaller (clypeus yellowish, long spot on lower frons laterally yellowish, fore coxa largely yellowish, pair of irregularly oval spots on gastral tergum II anterolaterally yellowish and evidently larger in A. ratzeburgi ).

Description. Male: Body length 4.0 mm. Head and thorax black; free margin of clypeus, labrum, base of mandible, maxillary palpus, labium, galea, flagellum beneath, and terminal portion of pronotal lobe yellowish brown; long spot on lower frons laterally light gray white. Largely yellowish brown are: fore coxa apically, fore trochanter, fore femur beneath, fore tibia beneath, mid coxa apically, mid trochanter beneath, mid femur beneath, mid tibia beneath, hind tibia beneath, and all tarsi; hind coxa largely black; remaining legs brown. Tergum I black, pair of round spots on gastral tergum II anterolaterally light yellowish brown, pygidial plate yellowish brown, remaining gaster brown or dark brown. Head and thorax (except propodeal enclosure glabrous) with sparse or dense, white to light brown, short setae; terga I and II with sparse, yellowish brown or light brown, long setae, remaining terga with sparse or dense, yellowish brown or light brown, long setae ( Fig. 2A View FIGURE 2 ).

Head: Vertex with dense, large punctures; frons with dense, median sized punctures, median furrow shallow ( Fig. 2B View FIGURE 2 ). Clypeus length: width = 10: 43, with dense, small punctures, slightly bulging anteromedially, free margin of clypeus straight ( Figs 2B, 2C View FIGURE 2 ). Free margin of labrum with broad, deep depression medially ( Fig. 2C View FIGURE 2 ). Mandible with one subapical inner tooth ( Fig. 2C View FIGURE 2 ). Flagellomere I slightly shorter than II, apical segment of flagellum depressed on inner side ( Fig. 2D View FIGURE 2 ). POL: OOL: OD = 5: 6: 3.

Mesosoma. Pronotal collar with dense, large punctures ( Fig. 2E View FIGURE 2 ). Mesoscutum with inconspicuous admedian and parapsidal lines, with broad depression on each side of scutum posteriorly ( Fig. 2E View FIGURE 2 ); scutellum and mesopleuron with sparse, large punctures, mesopleuron upper portion with broad, transverse furrow ( Fig. 2E View FIGURE 2 ). Metanotum with dense, large punctures; metapleuron polished, upper portion with sparse, small punctures ( Fig. 2F View FIGURE 2 ). Propodeum with triangular propodeal enclosure, pointed at end, as long as propodeal dorsum; enclosure with about 13 oblique longitudinal rugae and about 6 short transverse rugae posteriorly, propodeum outside of enclosure with about 12 oblique transverse rugae ( Fig. 2F View FIGURE 2 ); lateral surface of propodeum with sparse, large punctures and inconspicuous oblique rugae; posterior surface of propodeum with longitudinal median ridge and several oblique rugae. First recurrent vein received by submarginal cell II, second recurrent vein received by submarginal cell III ( Fig. 2G View FIGURE 2 ); hindwing vein M diverging after cu-a ( Fig. 2H View FIGURE 2 ).

Metasoma: Terga I and II polished, with sparse, small punctures; terga III–VI with dense, small punctures ( Fig. 2I View FIGURE 2 ); pygidial plate with dense, large punctures, terminal margin slightly arcuately protruded ( Fig. 2J View FIGURE 2 ).

Female: unknown.

Distribution. China ( Ningxia Autonomous Region).

Etymology. The new specific name, labrisectus , is derived from the labr- (labrum, Latin origin) and— sectus (dissected, Latin origin), referring to the central portion of the labrum free margin with a broad, deep depression medially, which is one of the important identifying characters of this species.